The present invention relates, in general, to electronics, and more particularly, to semiconductors, structures thereof, and methods of forming semiconductor devices.
In the past, singulation lines generally were formed as a plurality of parallel lines where each singulation line extended axially, such as along a long axis of the singulation line, from one side of the wafer straight across the wafer in order to allow wafer saws or scribe lines to extend in a straight line across the wafer. Each of the prior singulation lines generally extended straight across the wafer and did not have curves, bends, angles, or other shapes other than one continuous straight line. In order to facilitate using the straight singulation lines, prior semiconductor die generally had a regular shape such as all die having the same total area and the same shape that was usually a square or rectangular shape. The regular shaped die were also arranged in a regular pattern on a wafer so that the singulation lines could extend between the die and singulate the die. The straight lines of the rectangular or square shape and the same area of the die, along with the regular pattern, allowed using the straight singulation lines. These singulation lines forced die to have regular shapes of squares and rectangles in order to use these axially extending singulation lines.
Accordingly, it is desirable to have a method of forming a semiconductor die that does not require the axial singulation lines.
For simplicity and clarity of the illustration, elements in the figures are not necessarily to scale, and the same reference numbers in different figures denote the same elements. Additionally, descriptions and details of well-known steps and elements are omitted for simplicity of the description. As used herein current carrying electrode means an element of a device that carries current through the device such as a source or a drain of a MOS transistor or an emitter or a collector of a bipolar transistor or a cathode or anode of a diode, and a control electrode means an element of the device that controls current through the device such as a gate of a MOS transistor or a base of a bipolar transistor. Although the devices are explained herein as certain N-channel or P-Channel devices, or certain N-type or P-type doped regions, a person of ordinary skill in the art will appreciate that complementary devices are also possible in accordance with the present invention. It will be appreciated by those skilled in the art that the words during, while, and when as used herein relating to circuit operation are not exact terms that mean an action takes place instantly upon an initiating action but that there may be some small but reasonable delay, such as a propagation delay, between the reaction that is initiated by the initial action.
The use of the word approximately or substantially means that a value of an element has a parameter that is expected to be very close to a stated value or position. However, as is well known in the art there are always minor variances that prevent the values or positions from being exactly as stated. It is well established in the art that variances of up to at least ten percent (10%) (and up to twenty percent (20%) for semiconductor doping concentrations) are reasonable variances from the ideal goal of exactly as described. For clarity of the drawings, doped regions of device structures are illustrated as having generally straight line edges and precise angular corners. However, those skilled in the art understand that due to the diffusion and activation of dopants the edges of doped regions generally may not be straight lines and the corners may not be precise angles.
As used herein, symmetrical shapes means at least two shapes that have correspondence in size, shape, and relative position of parts on opposite sides of a dividing line or media plane or about a center or axis, a shape is symmetrical if it is unchanged by a reflection, or a rotation. The term asymmetrical means a shape that is not symmetrical, a shape is asymmetrical if it is changed by a reflection, or a rotation. The term rectangle means a closed planar quadrilateral with opposite sides of equal lengths, and with four right angles. Non-rectangular means a closed geometric shape that is not a rectangle. The term multiply-connected means an open set in the plane which has holes in it. A shape is multiply-connected if it has a hole through it, for example, a doughnut shape.